text: /*
   * Voltage Controller implementation for OMAP
   *
   * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
   *	Nishanth Menon
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed "as is" WITHOUT ANY WARRANTY of any
   * kind, whether express or implied; without even the implied warranty
   * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #include <common.h>
  #include <asm/omap_common.h>
  #include <asm/arch/sys_proto.h>
  #include <asm/arch/clock.h>
  
  /* Register defines and masks for VC IP Block */
  /* PRM_VC_CFG_I2C_MODE */
  #define PRM_VC_CFG_I2C_MODE_DFILTEREN_BIT	(0x1 << 6)
  #define PRM_VC_CFG_I2C_MODE_SRMODEEN_BIT	(0x1 << 4)
  #define PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT	(0x1 << 3)
  #define PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT	0x0
  #define PRM_VC_CFG_I2C_MODE_HSMCODE_MASK	0x3
  
  /* PRM_VC_CFG_I2C_CLK */
  #define PRM_VC_CFG_I2C_CLK_HSCLL_SHIFT		24
  #define PRM_VC_CFG_I2C_CLK_HSCLL_MASK		0xFF
  #define PRM_VC_CFG_I2C_CLK_HSCLH_SHIFT		16
  #define PRM_VC_CFG_I2C_CLK_HSCLH_MASK		0xFF
  #define PRM_VC_CFG_I2C_CLK_SCLH_SHIFT		0
  #define PRM_VC_CFG_I2C_CLK_SCLH_MASK		0xFF
  #define PRM_VC_CFG_I2C_CLK_SCLL_SHIFT		8
  #define PRM_VC_CFG_I2C_CLK_SCLL_MASK		(0xFF << 8)
  
  /* PRM_VC_VAL_BYPASS */
  #define PRM_VC_VAL_BYPASS_VALID_BIT		(0x1 << 24)
  #define PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT	0
  #define PRM_VC_VAL_BYPASS_SLAVEADDR_MASK	0x7F
  #define PRM_VC_VAL_BYPASS_REGADDR_SHIFT		8
  #define PRM_VC_VAL_BYPASS_REGADDR_MASK		0xFF
  #define PRM_VC_VAL_BYPASS_DATA_SHIFT		16
  #define PRM_VC_VAL_BYPASS_DATA_MASK		0xFF
  
  /**
   * omap_vc_init() - Initialization for Voltage controller
   * @speed_khz: I2C buspeed in KHz
   */
  static void omap_vc_init(u16 speed_khz)
  {
  	u32 val;
  	u32 sys_clk_khz, cycles_hi, cycles_low;
  
  	sys_clk_khz = get_sys_clk_freq() / 1000;
  
  	if (speed_khz > 400) {
  		puts("higher speed requested - throttle to 400Khz\n");
  		speed_khz = 400;
  	}
  
  	/*
  	 * Setup the dedicated I2C controller for Voltage Control
  	 * I2C clk - high period 40% low period 60%
  	 */
  	speed_khz /= 10;
  	cycles_hi = sys_clk_khz * 4 / speed_khz;
  	cycles_low = sys_clk_khz * 6 / speed_khz;
  	/* values to be set in register - less by 5 & 7 respectively */
  	cycles_hi -= 5;
  	cycles_low -= 7;
  	val = (cycles_hi << PRM_VC_CFG_I2C_CLK_SCLH_SHIFT) |
  	       (cycles_low << PRM_VC_CFG_I2C_CLK_SCLL_SHIFT);
  	writel(val, (*prcm)->prm_vc_cfg_i2c_clk);
  
  	/*
  	 * Master code if there are multiple masters on the I2C_SR bus.
  	 */
  	val = 0x0 << PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT;
  	/* No HS mode for now */
  	val &= ~PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT;
  	writel(val, (*prcm)->prm_vc_cfg_i2c_mode);
  }
  
  /**
   * omap_vc_bypass_send_value() - Send a data using VC Bypass command
   * @sa:		7 bit I2C slave address of the PMIC
   * @reg_addr:	I2C register address(8 bit) address in PMIC
   * @reg_data:	what 8 bit data to write
   */
  int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data)
  {
  	/*
  	 * Unfortunately we need to loop here instead of a defined time
  	 * use arbitary large value
  	 */
  	u32 timeout = 0xFFFF;
  	u32 reg_val;
  
  	sa &= PRM_VC_VAL_BYPASS_SLAVEADDR_MASK;
  	reg_addr &= PRM_VC_VAL_BYPASS_REGADDR_MASK;
  	reg_data &= PRM_VC_VAL_BYPASS_DATA_MASK;
  
  	/* program VC to send data */
  	reg_val = sa << PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT |
  	    reg_addr << PRM_VC_VAL_BYPASS_REGADDR_SHIFT |
  	    reg_data << PRM_VC_VAL_BYPASS_DATA_SHIFT;
  	writel(reg_val, (*prcm)->prm_vc_val_bypass);
  
  	/* Signal VC to send data */
  	writel(reg_val | PRM_VC_VAL_BYPASS_VALID_BIT,
  				(*prcm)->prm_vc_val_bypass);
  
  	/* Wait on VC to complete transmission */
  	do {
  		reg_val = readl((*prcm)->prm_vc_val_bypass) &
  				PRM_VC_VAL_BYPASS_VALID_BIT;
  		if (!reg_val)
  			break;
  
  		sdelay(100);
  	} while (--timeout);
  
  	/* Optional: cleanup PRM_IRQSTATUS_Ax */
  	/* In case we can do something about it in future.. */
  	if (!timeout)
  		return -1;
  
  	/* All good.. */
  	return 0;
  }
  
  void sri2c_init(void)
  {
  	static int sri2c = 1;
  
  	if (sri2c) {
  		omap_vc_init(PRM_VC_I2C_CHANNEL_FREQ_KHZ);
  		sri2c = 0;
  	}
  	return;
  }
  